An ethanol plant in Stockton, Calif. Analysts say a backup of railcars has kept ethanol from making it to coastal refineries that mix it into gasoline. U.S. ethanol and railroad industry groups clashed Thursday over transportation constraints that have triggered soaring prices for the biofuel in recent weeks. Renewable Fuels Association President Bob Dinneen said in a letter to the Association of American Railroads that the “sheer chaos” of the rail system has pushed up prices for ethanol—a corn-based biofuel that is blended into gasoline—and caused consumers to pay more at the pump. The higher costs, he argued, have damaged the image of the ethanol industry. Ethanol prices have jumped in recent weeks as supplies have declined amid transportation snarls. A bitterly cold winter and rising crude-oil shipments have slowed rail traffic in the Midwest. Most ethanol is made from corn grown in that region. The backup of railcars […]